The present invention relates to a recording and reproducing apparatus and an editing method for editing AV (Audio/Video) data and realtime metadata corresponding thereto by use of random-accessible recording media.
Especially, in professional scenes such as broadcasting stations, digital audio data and/or digital video data captured by video cameras and recorded to recording media are later edited as required before being actually used. Along with digital audio data and/or digital video data, realtime metadata that provides information thereabout is also recorded and used for editing. In what follows, these digital audio data and/or digital video data and realtime metadata will also be generically referred to as AV (Audio/Video) data. In one session of editing, desired video cuts are extracted from AV data reproduced from recording media, the start point (or the in-point) and the end point (or the out-point) of each extracted video cut are marked, and a plurality of video cuts are connected on the basis of the marked in-point and out-point, thereby providing a continuously connected video including desired video cuts.
In related-art technologies, recording media of serial access type such as magnetic tapes have been used for AV data recording and reproduction. Recently, random-accessible recording media such as optical disc, hard disc, and semiconductor memory have come to use for AV data recording and reproduction in many cases. Random-accessible recording media allow nonlinear editing in which an editing session may be completed on a same recording medium. In what follows, random-accessible recording media are referred to as nonlinear recording media. An editing apparatus for executing nonlinear editing is disclosed in Japanese Patent Laid-open No. 2001-319463
Generally, nonlinear recording media are very high in access speed as compared with serial-access recording media such as magnetic tape. Especially, hard discs are high in access speed and, at the same time, high in recording capacity, being capable of recording a huge amount of AV data. Optical discs and semiconductor memories having storage capacities large enough for recording plural pieces of AV data have recently emerged on the market. In these nonlinear recording media, the reproduction of the AV data between an in-point and an out-point for use in editing and the recording of the edited AV data may be executed concurrently with ease on one same recording medium and the edited AV data may be recorded to the same recording medium at another recording position with ease. Therefore, with nonlinear recording media, nondestructive editing in which an editing operation is executed with original AV data left remaining is practiced.
The following overviews related-art editing methods based on nonlinear recording medium. The related-art editing based on nonlinear recording medium is supported by one of the following two methods. In the first method, an entire edit result including a portion not subject to editing is written to a free space on a recording medium, as shown in FIGS. 18A and 18B for example. In the second method, only the AV data necessary for editing is written to a free space on a recording medium and control data is generated for giving an instruction for the continuous reproduction of this AV data and an area not subject to editing, as shown in FIGS. 19A and 19B for example.
As shown in FIGS. 18A and 19A for example, clip #1 and clip #2 are recorded in a logical space that is controlled by a file system FS by use of logical addresses and the remaining area in the logical space is handled as an unused area. It should be noted that a clip is a set of AV data; one clip is composed of the AV data generated between the starting of a video camera and the ending thereof, for example. A video clip includes digital video data taken by a video camera for example and digital audio data picked up at the same time as the video taking. Also, a clip may include metadata generated at the time of taking.
As shown in FIGS. 18A and 19A for example, an in-point and an out-point are set to clip #1. It is assumed that an insert editing is executed to insert a video cut into an interval subject to editing defined by these in-point and out-point.
In the first method, entire clip #1 inserted with a video cut between the in-point and the out-point of clip #1 is written to an unused area on the recording medium as clip #3 as shown in FIG. 18B. The original clip #1 is left at the original position in an unedited state. According to the first method, if there is an unused area large enough for editing, the results of editing may be continuously arranged in that unused area. In this example, no seek operation is executed at the in-point and the out-point, so that it is easy to guarantee realtime reproduction.
In the second method, only the data necessary for editing, namely, a video cut inserted between the in-point and the out-point is written to the unused area as shown in FIG. 19B (where this cut is indicated as video cut BR #3) and control data is generated to give an instruction for continuously reproducing a portion other than that outside the portion defined by the in-point and the out-point of clip #1 and video cut BR #3. The control data is recorded on the recorded medium as required. The second method is advantageous in that the amount of data to be recorded as a result of editing may only be minimal.